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Abstract: Corsica Island exhibited the particularity to display Teucrium flavum subsp. glaucum and subsp. flavum on the same territory with the same bioclimatic conditions. For the first time, volatile components extracted from aerial parts and genetic diversity of both Corsican T. flavum L. subspecies have been investigated through (i) the characterization of the chemical composition of essential oils and (ii) the study of three polymorphic genetic markers. Chemical analysis were performed using combination of capillary GC/RI, GC-MS after fractionation on column chromatography and the definition of the genetic structure were carried out using two chlororoplast markers (RPL32-TRNL and TRNL-F) and ribosomal nuclear markers (ITS region). According to statistical analysis, both subspecies were clearly distinguished by the chemical and genetic studies. Chemical compositions of oils from both subspecies were qualitatively similar but they differed by the normalized% abundances of their major components; oils from subsp. flavum were dominated by large amounts of hydrocarbon monoterpenes while oils obtained from subsp. glaucum were characterized by higher amounts of oxygenated compounds. The genetic analysis divided T. flavum L. populations in two groups, the first displayed subsp. glaucum populations and the latter group exhibited subsp. flavum populations. The presence of two groups is weakly consistent with chemical differentiation. These data suggest that the differences in the volatile composition of the two T. flavum subspecies depends more on the genetic background and less on environmental factors. [Copyright &y& Elsevier]

Abstract: Fifty Corsican “chestnut grove” honeys were certified by melissopalynological analysis. Castanea sativa was strongly overrepresented and was accompanied mainly by Rubus sp., Quercus ilex, Anthyllis hermanniae, Myrtus communis, Genista sp., Erica arborea, Cistus creticus, and Fraxinus ornus. Headspace solid-phase microextraction was performed to investigate the volatile composition of Corsican chestnut catkins and chestnut grove honeys. The main compounds of the chestnut catkins were acetophenone (21.5%), methyl salicylate (13.4%), nonanal (10.9%), and linalool (7.5%), whereas the major constituents of the honeys were 2-aminoacetophenone (11.4%), benzaldehyde (10.8%), acetophenone (7.0%), nonanoic acid (5.9%), octanoic acid (5.0%), and 3-furaldehyde (4.9%). By entering the aromatic intensity, the relative frequency of C. sativa, Rubus sp., and A. hermanniae pollens, and the physicochemical parameters as discriminate variables, principal component analysis (PCA) and cluster analysis (CA) showed that the distribution of Corsican “chestnut grove” honeys correlates with climatic events and/or honeybee foraging behaviours. [Copyright &y& Elsevier]

Chemical and genetic diversity of Teucrium polium L. subsp. polium from western Algeria and T. polium L. subsp. capitatum from Corsica were investigated. Diversity within and among the two populations of subspecies was assessed according to the chemical composition of their essential oils and the genetic diversity. Chemical analysis was performed using a combination of capillary GC-RI and GC/MS after fractionation using column chromatography. Genetic structures were mapped using three polymorphic genetic markers: two chloroplast markers (RPL32-TRNL and TRNL-F) and ribosomal nuclear markers (ITS region). The statistical analysis showed that both subspecies were clearly distinguished by these chemical and genetic markers. The oil chemical compositions differed qualitatively and quantitatively between the subspecies. Both collective oils were dominated by hydrocarbon compounds however the Algerian sample oils exhibited higher amounts of hydrocarbon sesquiterpenes than those of Corsica (31.2 g/100 g vs. 4.4 g/100 g) while the latter displayed higher amounts of hydrocarbon monoterpenes than the first (59.3 g/100 g vs. 34.3 g/100 g). Neighbor-joining, Maximum likelihood and Bayesian trees constructed from chloroplast markers and nuclear ITS region sequences showed the existence of two groups associated with taxonomic and chemical characteristics. The study indicated that variation in the essential oil composition within subspecies depends on genetic background. The samples of subsp. capitatum from Corsica are a homogeneous group, in contrast to samples of subsp. polium from Algeria which were clustered in two groups. Chemical and genetic diversity of Algerian populations could be explained by geographical isolation of the populations. In addition, the morphological polymorphism observed throughout the colour of flowers could be explained by environmental parameters as well as the soil pH., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Chemical and genetic diversity of Teucrium scorodonia L. subsp. scorodonia from Corsica and T. scorodonia L. subsp. baeticum from western Algeria were investigated. Diversity within and among the two populations of subspecies was assessed according to the chemical composition of their essential oils, and genetic diversity was evaluated using three polymorphic genetic markers. Chemical analysis was performed using a combination of capillary GC-RI and GC/MS after fractionation using column chromatography. Genetic structures were mapped using two chloroplast markers (RPL32-TRNL and TRNL-F) and ribosomal nuclear markers (ITS region). The statistical analysis showed that the two subspecies were clearly distinguished by these chemical and genetic markers. The chemical composition of oil differed qualitatively and quantitatively between the subspecies. Corsican oil samples contained germacrene B (4.2-8.8%) and γ-elemene (2.6-5.7%), which were not detected in Algerian oil samples. The oils of the scorodonia and baeticum subspecies were dominated by sesquiterpene hydrocarbon compounds (75.6-82.9% and 69.6-79.4%, respectively), but they differed in oxygenated sesquiterpene content (3.1-8.9% and 8.4-20.3%, respectively). Neighbor-joining trees constructed from chloroplast DNA and ITS region sequences showed the existence of two groups associated with taxonomic and chemical characteristics. One group consisted of T. scorodonia subsp. scorodonia and the other of T. scorodonia subsp. baeticum, indicating that variation in the essential oil composition of T. scorodonia subspecies depends more on genetic background than environmental characteristics., (Copyright © 2011. Published by Elsevier Ltd.)